SpaceX is moving full-speed ahead with the Big Falcon Rocket (BFR) project with the aim of sending a Japanese fashion tycoon on a moon mission in 2023. That’s not the only thing CEO Elon Musk has planned for the BFR. In his characteristically off-handed way, Musk noted on Twitter that he thinks SpaceX can have a Mars base built by 2028. NASA meanwhile questions whether it’s feasible to even launch a manned Mars mission in the 2030s.
The Twitter exchange doesn’t contain much information. Several days ago, Musk tweeted a new rendering of a Mars base with BFR rockets landed nearby. Someone asked when such a thing was likely to happen, and Musk said 2028.
This timeline loosely matches what SpaceX has said about its BFR plans in the past. The first test flights should take place in the coming years so the company can confirm the BFR works before stuffing people into it. In past speeches, Musk has said SpaceX plans to send a pair of unmanned BFR spacecraft to Mars in 2022, followed by two more in 2024. That year could also see two crewed BFR rockets head to the red planet. Each of the unmanned rockets could carry up to 100 tons of supplies to begin building the colony. These six rockets would form the backbone of an early base that would expand as more people move there.
SpaceX has only started building the first BFRs, which will be reusable spacecraft. A lot could still go wrong, and even small delays can cause significant changes in the timeline. It’s only efficient to fly to Mars at certain times as the two planets’ orbits bring them in close proximity. Missing a deadline by a few weeks could push back a mission timeline by months or years.

Getting a human city built on Mars within a decade is ambitious — we’re talking 1960s moon landing ambitious here. Not only does SpaceX need to develop and test a new rocket to make the journey, it needs to figure out how people can survive on Mars. Radiation poses a serious risk for long-term health on Mars, for example. Even fundamental issues are up in the air, like whether it’s possible to extract significant water from Mars. SpaceX has suggested in the past that colonists would need to extract a ton of ice each day to become self-sufficient and ensure the BFRs could be refueled for a return trip. Living on Mars could be difficult if a human settlement relies entirely on water hauled over from Earth.
We’ll have a better idea how likely this timeline is as the BFR takes shape. If the manned moon mission ends up delayed, it’s unlikely a Mars base is happening within a decade.